I know this is an old thread but I am getting a 30amp BCS 460 panel from Ebrewsupply, i have 30 amp service to the brew room. So a 50 amp panel will not offer GFCI protection? I am having a hard time finding a 30 amp panel. May be cheaper to put a GFCI breaker in the box?

Assuming he matched his wiring sizes to the 30a breaker in the main, the spa panel will NOT offer overcurrent protection. The wiring could cook long before the 50a breaker trips. The 30A breaker at the main panel provides the overcurrent protection, the 50a GFCI would only provide GFCI protection.

Most spa panels do not offer overcurrent protection anyway...it seems to be a bit of a misnomer to call them 'breakers', the number on the box is only a current rating for the disconnect. The GFCI disconnects in them will work with any load UP TO what they are rated, and still operate as desired. They will still trip with a 2A load if there is a ground fault.